This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The objective of the "Structure and Dynamics by Multi-frequency ESR" workshop was to raise awareness in the biomedical community to the advantages of multi-frequency ESR for studying biological, biomimetic and other systems. The speakers shared their experience and recent progress in applications of detailed multi-frequency studies to reveal molecular-level structures and interactions, motional dynamics and orientation, and relevant modeling. As usual with our workshops, this Workshop featured examples of techniques in action, problems solved by multi-frequency techniques, as well as directions for the future;sample preparation, data collection and spectral analysis. Invited speakers presented talks designed to highlight recent progress in these areas and promote discussion of current needs. There were 25 registered participants from outside of ACERT, 14 ACERT staff members who attended, and 7 outside guest speakers for a total of 46 participants.